Some people I know are giving me a 1986 Chevrolet Cavalier, I don't know if it's 2 or 4 door, VIN #, or miles on it. They tell me that it is driveable but makes a little clunk noise when first put in reverse, but once it starts moving the noise is gone. They think it's the CV boot. Can anyone help me as to what could be making the noise and approximately how much it would cost to fix? It's a 5 speed standard.